NEVER
disassemble the fuel flow sensor. The sensor is factory sealed, and disassembly
will void the product warranty. If you feel that the sensor is not
functioning correctly, please contact Maretron Technical Support.

Operating Principle

When
fluid passes through the sensor, the rotors turn, as shown in the figure on the
right. Magnets which are located in the rotors will pass across sensors in the
sensor circuit board. Pulses from these sensors are transmitted to the FFM100
which performs flow rate calculations based on the received pulses.

1.The fuel flow sensors are
compatible with fuel, lubricating oil, hydraulic fluid, or other clean
petroleum based products and should not be used with any other fluid types.

2.The fuel flow sensor contains
shafts on which the oval rotors spin. The fuel flow sensor must be mounted so
that these rotor shafts are always in a horizontal plane (parallel with the
ground or water surface). The rotor shafts are parallel to the screws attaching
the sensor cap to the sensor base, so ensure that these screws are in a
horizontal plane. Please refer to Figure 1 below for examples of correct and
incorrect orientations.

Figure
1 - Correct and Incorrect Mounting Orientations

3.To prevent damage from dirt or
foreign matter, it is required that either 1) a diesel fuel filter capable of
filtering out 75 micron particles or 2) a Y or basket type 60 mesh strainer be
installed as close as possible to the inlet side of the sensor.

4.Install so that the direction of
the “FLOW” arrows on the sensor label matches the direction of fuel flow.

6.Use a liquid thread sealant on all
pipe threads. Do NOT use Teflon tape. The fittings should be tightened
hand tight, then a further 1/2 to 1 turn. Do not over tighten.

7.Extreme care must be taken when
installing the sensor. Pipe strain or over tightening sensor connections can
cause sensor damage.

8.To prevent damage to the sensor
from entrapped air during initial commissioning or after maintenance, slowly
fill the system with fuel (this will prevent damage caused by air purge).
Failure to do this could damage the sensor. NEVER blow or send compressed air
through the sensor as this may over rev and damage the sensor.

9.Connect the six wires of
the pressure transducer to a free pressure monitoring channel. Please refer to Figure 2 below for details.

10.Use a Maretron DSM250
display (firmware 1.4.12 or higher), Maretron N2KAnalyzer software, or other
Maretron display product capable of configuring the FFM100 to configure the
connected channel. Please refer to the FFM100 User’s Manual for configuration
details. Be sure to program the FFM100 with the K factor printed on the fuel
flow sensor.

11.Supply
Power to the NMEA 2000 network and verify that the flow channel indicates a
valid flow rate and temperature reading.